#include <bits/stdc++.h>
using namespace std;
#include <atcoder/math>
using namespace atcoder;

#define rep(i, n) for( ll i = 0; i < n; i++ )
using ll = long long;

int main() {
	int N;
	string s;
	cin >> N >> s;
	string ans = "NotFound";
	rep(i, N) {
		if(i + 2 < N && s.substr(i, 3) == "404") ans = "Found";
	}
	cout << ans << endl;
}